DR is short for Digital Radiography. The chest DR radiography image is the replacement of the traditional chest perspective imaging, whose imaging sharpness is high and the radiation is low. X-ray imaging is the major measures of the medical screening for the pulmonary diseases, which include the pulmonary inflammation, lump, tuberculosis, lung cancer and so on. The chest DR radiography utilizes the image difference for the density difference of the human tissue under X-ray to observe the lesion of the parts with slight difference between the thickness and density. However, the structure of human tissue is complicated. The thoracic cavity and enterocoelia include the key organs of the human body, which include all kinds of visceral organs with high density and low density. Therefore, the images of all organs and tissues overlap with each other, which have quite a large influence on the observation and judgment. So the reading and judgment of the DR radiography have very high requirement on the experience of the doctors and the large scale DR radiography examinations are very hard to be launched in the primary hospitals and medical examination points
In the resident medical examination, normally the aim of shooting DR radiography is to conduct the tuberculosis screening. The tuberculosis is caused by the mycobacterium tuberculosis, which is easily spread through spray in the air and even the aerosol. The majority of tuberculosis patients is young adults, which will result in the labor loss for the families and the society. The world health organization indicates that the tuberculosis is the important public health problem all over the world. Every year the tuberculosis kills 140,000 people all over the world. In our country, there are approximate 5,000,000 active pulmonary tuberculosis patients at present and there are approximate 50000 people die of tuberculosis every year. In accordance with the estimation of the world health organization, there are approximate 1,000,000 new patients in our country, for which the annual progressive decrease range is 3%. In 22 countries with high burden of the tuberculosis all over the world, our country ranks only second to India. The tuberculosis is one of the major infectious diseases which are importantly prevented and controlled by our country. The Chinese Center for Disease Control and Prevention indicates that our country is one of 22 countries with high burden of the tuberculosis all over the world and one of 27 countries with high burden of the multi-drug resistant tuberculosis all over the world, whose number of multi-drug resistant tuberculosis patients is the highest one of the whole world; The number of ordinary tuberculosis patients ranks only second to India all over the world.
Although the tuberculosis epidemic in our country presents a serious situation with a large number of infected people, large incident number and large number of current patients, the tuberculosis can be prevented and cured with the modern medical help. In consideration of the fact that the damage of the tuberculosis is serious and the difficulty of the prevention and control work is enormous while the scale of local tuberculosis prevention and control teams at different levels is still small, whose power and expenditure cannot adapt the prevention and control demand, the technology and capital input shall be strengthened and the medical prevention combination mechanism shall be established to form the practical and effective prevention and treatment system. At present, two weak and difficult links of early-stage notice and treatment management exist in the implementation of the prevention and treatment for the tuberculosis. Under such circumstance, the screening program for the tuberculosis patients among the focus groups is gradually launched inside the country by using the essential public health service and free antituberculosis therapy is given for all diagnosed patients.
Being compared with the tuberculosis, the severity degree of damage to the lung cancer on the health of the patients is higher than that of the former. It is commonly acknowledged that the death rate of lung cancer is considerably higher than that of other cancers and it increases by years in recent years. The imageological examination is one of the important technical measures in the aspects of diagnosis, test, prevention and treatment on the cancer. The generally major research object of chest imaging is the lung cancer, which normally observes the corresponding lung images through establishing the lung window. Lung cancer is a neoplastic disease which is related to the smoking, tmospheric pollution and low immunologic function. For example, the repeated inflammatory stimulation of factors like the haze in recent years will bring the chronic damage, affect the normal epithelial function of the bronchial epithelium and the immune antiviral state of the body and have facilitation affect on the occurrence of lung cancer, which may result in the high occurrence of lung cancer in the future. In addition, the carcinogenic incubation period of lung cancer is very long, which normally takes 10 to 30 years. Therefore, some people who ever had tuberculosis when they were young will have the calcification left in their lung after cure and they may mistakenly regard the shadow found in their lung as the calcification due to the tuberculosis in the future medical examination. Consequently, they may miss the chance of early detection of lung cancer.
Being compared with the pulmonary tuberculosis complicating lung cancer, the lung cancer complicating tuberculosis may need more attention. The statistics show that there are about 10%˜15% of the lung cancer patients will have tuberculosis incidence and the autopsy cases reach as much as about 30%, which is resulted from the reason that partial lung cancer and tuberculosis are difficult to be distinguished in the imaging and misdiagnose, therapeutic error or delay treatment are extremely easy to happen on clinic. Some patients on clinic only have tuberculosis but they are diagnosed as having lung cancer in several primary hospitals with a imaging examination only. What's the worse, the chemoradiotherapy is conducted for them blindly, which result in serious damage on the body of the patients. On the contrary, some patients do have the lung cancer with complicating tuberculosis but they are diagnosed as the tuberculosis and receive the treatment as that of the pure tuberculosis only. Such phenomenon is mainly resulted from the reason that the clinical manifestations of the tuberculosis and that of the lung cancer are similar, which are cough, hemoptysis and etc. Also, both of them can be shown as the shadow on the chest X-ray radiography through imaging examination.
One large difficult point of the intelligent treatment for the lung DR radiography is the method of confirming the area of the lung lobe. If the scope of lung lobe can be accurately confirmed and the interference outside the lung can be weakened or eliminated, it will be more beneficial for the notice of the slight lesion. In addition, the shape of the lung lobe contour itself also is a important factor for judging relevant physiological index of the people receiving physical examination; Reliable lung lobe contour extraction algorithm can reduce the time of rechecking for the people receiving physical examination and reduce the number of chest images, letting them obtain the definite diagnosis on their nidus from the doctors at the cost of lower radiation dosage.